The Present invention relates to an axle and ball bearing arrangement for bicycle, and more particularly to such an axle and ball bearing arrangement that can be quickly installed in a bottom bracket for a bicycle.
Ball bearing means are intensively used in bicycles to support rotary members. FIG. 1 shows steel balls arranged in holes in a ball cup. When the ball cup is installed in a bottom bracket to support a bottom bracket bearing axle, the steel balls are disposed in contact with the periphery of the bottom bracket bearing axle. Because the steel balls can only be rotated in the respective holes in the ball cup, the bottom bracket bearing axle receives much resisting force from the steel balls when rotated. Further, the installation of the steel balls and the ball cup consumes much labor. FIG. 2 illustrates an axle and ball bearing arrangement installed in a bicycle's bottom bracket according to the prior art. This arrangement comprises a bottom bracket bearing axle having a locating flange raised around the periphery, a ball race fastened to a bottom bracket to hold a plurality of steel balls on the inside around the bottom bracket bearing axle between the locating flange of the bottom bracket bearing axle and an inside annular flange inside said ball race, and a plastic annular insert fastened to the ball race around the bottom bracket bearing axle to hold the steel balls in place. This arrangement has drawbacks. One drawback of this arrangement is that lubricating grease tends to leak out of the ball race. Another drawback of this arrangement is that the plastic annular insert wears quickly with use. When the plastic annular insert starts to wear, the steel balls may be vibrated when rotated. Furthermore, because the steel balls are separately packed, much time is wasted in assembling the transmission system during the assembly process of the bicycle.
This present invention has been accomplished to provide an axle and ball bearing arrangement which eliminates the aforesaid drawbacks. According to one aspect of the present invention, a annular locating member is mounted around a bottom bracket bearing axle within a ball race to hold steel balls inside the ball race around the bottom bracket bearing axle between a flange around the periphery of the bottom bracket bearing axle and a flange around the inside wall of the ball race, and a dust cap is fastened to the ball race at one side opposite to the annular locating member. Because the steel balls are received in an enclosed space, no lubricating grease will leak out. Because the bottom bracket bearing axle, the annular locating member, the steel balls, the ball race and the dust cap are assembled together at the factory, bicycle assembly process can efficiently be Processed.